This statistic hides an even more disheartening reality. Close to 2 billion people suffer from micronutrient malnutrition, commonly called "hidden hunger" because it is less obvious than regular hunger.

Since it is harder to identify visually, hidden hunger gets far less attention than it warrants. Micronutrient malnutrition causes many of the same health problems as calorie deficiency hunger. Hidden hunger is particularly detrimental to young children, women of childbearing age, and the poorest parts of populations in developing countries. Like regular hunger, it costs millions of lives each year and prevents an even greater number from escaping poverty.

As a development researcher, I have witnessed firsthand the consequences of hidden hunger. I have also observed many ingenious solutions that can effectively, affordably and swiftly solve many of the problems that cause hidden hunger. With enough attention and support, hidden hunger can be erased in a few decades, significantly improving the lives of nearly a third of the world's population.

What is micronutrient malnutrition?

Hundreds of millions of children around the world suffer the effects of hidden hunger.Discha-AS

The body needs far more than just calories to function and develop properly. Vitamins and minerals are essential to many of the body's core functions, such as immune system health and brain function. When the calorie intake is not varied, it is entirely possible to eat sufficient calories without having sufficient micronutrient nutrition. That is, a person can have enough calories but still be malnourished.

A zinc deficiency can cause the body to develop too slowly and can damage the central nervous system, and it lowers the body's ability to fight diarrheal disease. There are 1.7 billion cases of diarrheal disease around the world each year, and it is the second most prevalent cause of death among children under 5. Diarrheal disease compounds the micronutrient malnutrition damage because the body struggles to make full use of available calories and micronutrients, leading to even greater levels of malnutrition.

Children suffering from hidden hunger in early childhood are less likely to complete their education, more likely to suffer from chronic disease, and are consequently less productive. This affects their ability to escape poverty and malnutrition later in life, passing the vicious cycle on to their own children.

Almost anyone can immediately recognize the consequences of regular hunger. For many years aid organizations, NGOs and others have leveraged the widespread imagery of stunted children with distended bellies as a call to arms against hunger. The visible suffering triggers compassion in most people and serves as a call to action.

Micronutrient malnutrition earned the nickname hidden hunger because, although it has many of the same long-term health consequences, it is difficult to identify, even for people suffering from it. Many of the consequences, such as lower cognitive function, accrue over a lifetime and they are hard to attribute directly to a specific deficiency. But, they are just as real.

How can we fix it?

The ideal solution to micronutrient deficiency is a diverse diet, rich in different grains, meats and vegetables, like the food pyramid recommended by many health agencies around the world. While this would satisfy most micronutrient needs, a diverse diet is prohibitively expensive for many people, who would have to give up calories to afford better foods, effectively trading one type of hunger for another.

Other and much more feasible and affordable solutions exist. In Tanzania, situated near the equator in sub-Saharan Africa, most people depend on a single staple - maize - for more than 80 percent of their calories. It is the only affordable way for most people to consume enough calories. Maize, just as with other staples like rice, wheat, cassava and millet, is almost entirely void of micronutrients. What little micronutrient content a whole maize kernel holds is largely lost during the milling process to make maize flour, the most common form of maize consumption in East Africa and much of Latin America.

The simple solution to improving the nutritional value of these staple goods is to fortify them with a mix of micronutrients. After or during the milling process, a safe and inexpensive micronutrient powder can be added by the miller, or by consumers themselves, drastically boosting the nutritional value. Despite recent increases in attention to the importance of hidden hunger, comprehensively fortifying staple goods is still a long way away for most developing governments, which lack the funds, expertise and occasionally the political will, to ensure fortification. Without substantial subsidies, millers can only fortify staples when they can pass at least part of the cost onto consumers. For many people living in abject poverty, even a small increase of a few percent in the cost of food is prohibitive.

Food fortification is the most cost-effective way to help hundreds of millions of people simultaneously improve quality of life, health and education, and to escape poverty. It is far more cost-effective than the typical aid programs that are aimed at incremental improvements in just one of these areas. With enough attention and support, hidden hunger can be erased in a few decades, significantly improving the lives of nearly a third of the world's population.

Morten Wendelbo does not work for, consult, own shares in or receive funding from any company or organization that would benefit from this article, and has disclosed no relevant affiliations beyond their academic appointment.